Portable Cutting Device With Blade Guard

ABSTRACT

A portable cutting device having a cutting tool for cutting a material. The cutting device includes a motor driving the cutting tool and a shroud at least partially enclosing the cutting tool. The shroud defines a debris accumulation chamber for gathering debris created by the cutting tool cutting the material. An impeller is operatively coupled to the motor and driven by the motor to create suction pressure to draw the debris out of the debris accumulation chamber and into a collection bag.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/136,903, filed Dec. 20, 2013, which is a divisional of U.S. patentapplication Ser. No. 12/767,687, filed Apr. 26, 2010, entitled “PORTABLECUTTING DEVICE WITH ON-BOARD DEBRIS COLLECTION,” which claims priorityto and all benefits of U.S. Provisional Patent Application No.61/172,607, filed Apr. 24, 2009, entitled “PORTABLE CUTTING DEVICE WITHON-BOARD DEBRIS COLLECTION,” the complete disclosures of all of whichare hereby incorporated by reference. The complete disclosure of U.S.patent application Ser. No. 10/939,440, filed Sep. 14, 2004, entitled“SELF-CONTAINED VACUUM SAW,” now U.S. Pat. No. 7,328,512, is also herebyincorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a cutting device for cutting a materialsuch as wood, drywall, concrete, roof tiles, slate, etc, which createsdebris. More specifically the present invention relates to the cuttingdevice having a rotatable blade guard.

BACKGROUND OF THE INVENTION

Portable cutting devices are well known in the art of carpentry andconstruction. Such devices include portable circular saws, concretesaws, routers, and the like. When using these devices to cut throughmaterials such as wood, drywall, concrete, roof tiles, slate, etc.,cutting debris is created, e.g., saw dust, concrete dust and largerparticles. In most cases, protective gear is needed to avoid healthhazards associated with this debris. Additionally, the debrisaccumulates in the area in which the cutting device is being used makingclean-up time consuming and difficult. Accordingly, there is a need forportable cutting devices with debris collection systems to collect thedust and larger particles.

Prior art portable cutting devices have been developed to include debriscollection systems. These systems typically include a housing defining adebris accumulation chamber and a collection port on the housing forconnecting to a vacuum source. The vacuum source draws the debristhrough the collection port into a collection area. The vacuum source isoff-board, meaning that the vacuum source is separate from the cuttingdevice. As a result, when transporting the cutting device between worksites, a vacuum source must be made available at each of the work sites.

SUMMARY OF THE INVENTION AND ADVANTAGES

A cutting device having a cutting blade for cutting material isprovided. A motor drives the cutting blade. A shroud at least partiallyencloses the cutting blade. The shroud defines a debris chamber intowhich material debris generated by the cutting blade during cutting isreceived. A source of vacuum is in fluid communication with the debrischamber. A vacuum conduit defines a vacuum path extending between thedebris chamber and the source of vacuum. A blade guard is rotatablerelative to the shroud from an extended position outside of the shroudto a retracted position inside of the shroud. The blade guard defines anopening configured to provide communication between the debris chamberand the vacuum conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

Other advantages of the present invention will be readily appreciated,as the same becomes better understood by reference to the followingdetailed description when considered in connection with the accompanyingdrawings wherein:

FIG. 1 is a right-side front perspective view of a portable cuttingdevice;

FIG. 2 is a right-side front perspective view of the portable cuttingdevice in an angled state;

FIG. 3 is a left-side front perspective view of the portable cuttingdevice in an angled state;

FIGS. 4A and 4B right-side front perspective exploded views of theportable cutting device;

FIG. 5 is a front view of drive train components and blade of theportable cutting device;

FIG. 6 is a left-side rear perspective view of the motor casing of theportable cutting device;

FIG. 7 is a right-side front perspective view of the motor casing of theportable cutting device;

FIG. 8 is a left-side front perspective view of the left-hand handlehalf;

FIG. 9 is a right-side front perspective view of the right-hand handlehalf;

FIG. 10 is a partial right-side front perspective exploded view ofvacuum housing-related components of the portable cutting device;

FIG. 11 is a left-side rear perspective exploded view of the vacuumhousing of the portable cutting device;

FIG. 12 is a right-side front perspective view of the vacuum housing ofthe portable cutting device;

FIG. 13 is a right-side front perspective view of the impeller and itsdrive shaft;

FIG. 14 is a right-side front perspective view of the upper bladeenclosure;

FIG. 15 is a fragmented sectional view of the upper blade enclosure andthe retracted lower blade guard, and the saw blade;

FIG. 16 is a partially sectioned, front view of the drive traincomponents and vacuum conduits of the portable cutting device;

FIG. 17A is a right-side front perspective exploded view of the lowerblade guard and its bearing;

FIG. 17B is a left-side view of the lower blade guard and its bearing;

FIG. 18 is a right-side front perspective view of the transparent sidewindow of the portable cutting device;

FIG. 19 is a right-side front perspective view of the main bellows;

FIG. 20 is a right-side front perspective view of the transparent bladewindow;

FIG. 21 is right-side front perspective view of the rear bellows;

FIG. 22 right-side front perspective view of the lower bellows;

FIGS. 23A and 23B are fragmented front views of the portable cuttingdevice in a zero angled state, at comparatively greater and lesser bladedepth positions, respectively;

FIGS. 24A and 24B are fragmented front views of the portable cuttingdevice in a 45-degree angled state, at comparatively greater and lesserblade depth positions, respectively;

FIG. 25 is an enlarged, fragmentary front view of the portable cuttingdevice in a 45-degree angled state; and

FIG. 26 is a fragmented front view similar to that of FIG. 24B, but witha portion of the base plate removed to reveal the lower bellows.

It is to be noted that the Figures are not necessarily drawn to scale.In particular, the scale of some of the elements of the Figures may beexaggerated to emphasize characteristics of the elements. It is alsonoted that the Figures are not necessarily drawn to the same scale.Elements shown in more than one Figure that may be similarly configuredhave been indicated using the same reference numerals.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and may herein be described in detail. It shouldbe understood, however, that the drawings and detailed descriptionthereto are not intended to limit the invention to the particular formdisclosed, but on the contrary, the intention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a portable cuttingdevice for cutting a material M such as wood, drywall, concrete, rooftiles, slate, etc., is generally shown at 30. The cutting device 30 isdefined as being portable because of the ability to easily move thecutting device 30 between work sites. The cutting device 30 preferablyweighs less than 50 lbs, more preferably less than 35 lbs, and mostpreferably less than 20 lbs. The cutting device 30 is also preferablyhandheld, such that it can be maneuvered, lifted etc. with a singlehand.

Referring to FIGS. 1-4B, the cutting device 30 includes saw casing 31 inwhich is disposed a motor 32 which drives a cutting tool 34. The motor32 is preferably electrically powered and energized by a 110-volt outletthrough a conventional electrical cord C, but the motor 32 could also bebattery operated. The motor 32 has a main drive shaft 36 and the cuttingtool 34 is operatively coupled to the main drive shaft 36 to rotate uponoperation of the motor 32.

The cutting tool 34 shown is a circular saw blade 34 that rotatescounterclockwise, in the direction of arrow 24, to cut up through thematerial M. The saw blade 34 could be configured for cutting throughwood, metal, concrete, roof tiles, slate, and the like. The saw blade34, which is of a common type known to those of ordinary skill in theart, is generally circular and defines a central aperture for engaging arotational saw shaft 116, as best shown in FIG. 6.

The main drive shaft 36 drives the saw shaft 116 through a transmission.The transmission includes a first gear 320 fixed to the main drive shaft36 and a second gear 322 fixed to the saw shaft 116. The gears 320, 322are preferably configured to step down rotational speed of the saw shaft116 compared to the main drive shaft 36. The transmission is disposed intransmission casing 35 (described further below) that covers, secures,and protects its gears 320, 322, with a sealed bearing disposed intransmission casing 35 to support the saw shaft 116. The motor casing 38and transmission casing 35 together form a drivetrain housing.

A gear plate 51 defines part of the transmission casing 35 and includesa fixed collar 206 that covers and supports the sealed bearing 204,through which extends saw shaft 116 supported thereby. The gear plate 51includes a base 53 on which outer fixed collar 206 is disposed and fromwhich collar 206 extends laterally outwardly. Saw blade 34 is clampedbetween an adjacent flange 55 and a bolt or nut 37 that engages threadsformed in or on the end of the saw shaft 116 in the well-known manner,thereby rotatably fixing the saw blade 34 to the saw shaft 116.

Referring to FIGS. 2-4B, the motor 32 includes a motor casing 38 thatencloses and supports the motor components, e.g., brushes 32 a, stator32 b, and rotor 32 c. The motor casing 38 defines a motor cavity 39 forreceiving the stator 32 b and rotor 32 c and a pair of cavities 41 forreceiving the brushes 32 a. The motor components 32 a, 32 b, 32 c aresecured in the motor cavities 39, 41 using methods well known to thoseskilled in the art, such as by fasteners, clips, snap-fits,interference-fits, and the like. The motor casing 38 is preferablyformed of metal and includes a vent 40 for exhausting heat generated bythe motor 32. In other embodiments, the motor casing 38 could be formedof a rigid plastic material suitable for supporting the motor 32.

Referring to FIGS. 2, 8, and 9, a handle 42 is fixed to the motor casing38. A user grasps and holds the handle 42 to manipulate, maneuver andoperate the cutting device 30 during use. A trigger 44 energizes themotor 32 using conventional methods. The handle 42 supports the trigger44 for actuation by the user. As shown in FIGS. 8 and 9, the handle 42is preferably formed in two mating halves 42 a/42 b that are lockedtogether (via adhesive, mating studs/bores, and/or the like). The handle42 defines a rear cable port 48 for receiving the cord C.

The motor casing 38 defines a cylindrical outer surface 50 (see FIG.4B). The handle 42 defines a cylindrical inner surface 52 that surroundsand engages motor casing surface 50. A suitable adhesive could be usedto secure the handle 42 to the motor casing 38. Mid-body motor casingenclosure 46 is disposed on motor casing 38 adjacent to left-hand handlepart 42 b, and forms part of saw casing 31. Mid-body motor casingenclosure 46 has inner cylindrical surface 47 that surrounds and engagesmotor casing surface 50. A suitable adhesive could be used to secureenclosure 46 to the motor casing 38.

A lower platform assembly 54 is coupled to the motor casing 38. Thelower platform assembly 54 comprises an upper plate or deck plate 56,and a lower plate or base plate 58, which are pivotally coupled togetherthrough pivoting or hinged joints 60. The upper plate 56 defines agenerally rectangular blade opening 62 for receiving a lower portion ofthe saw blade 34. The lower plate 58 similarly includes a generallyrectangular blade opening 64 for receiving the lower portion of the sawblade 34. The lower plate 58 is adapted to contact and slide along thematerial M being cut by the saw blade 34.

A depth adjustment block 66 is fixed to the upper plate 56. The depthadjustment block 66 defines an elongated slot 68 for receiving anadjustment screw 70 therethrough. A corresponding depth adjustmentbracket 72 (FIG. 4B) is fixed to handle 42. The depth adjustment bracket72 defines a threaded bore 74 for threadably receiving the adjustmentscrew 70. The adjustment screw 70 has a graspable head or pommel 69 anda threaded shaft wherein the threaded shaft fits through the elongatedslot 68 and threads into the threaded bore 74. When tightened, thegraspable head 69 frictionally engages an outer surface of the depthadjustment block 66 to hold the depth adjustment block 66 in one of aplurality of adjustable positions by frictionally securing the depthadjustment block 66 between the depth adjustment bracket 72 and thegraspable head 69. As a result, the lower platform assembly 54 can beadjusted for depth relative to the motor casing 38 via the adjustmentscrew 70.

Referring to FIGS. 1, 2, and 4A, a first angle adjustment block 71 isfixed to the upper plate 56 and a second angle adjustment block 73 isfixed to the lower plate 58. The first angle adjustment block 71 definesa bore 76 for receiving an angle adjustment screw 78. The angleadjustment screw 78 has a threaded shaft and a graspable head 81configured to form a lever. A wing nut 80 threadably engages thethreaded shaft of the angle adjustment screw 78 on a rear surface of thefirst angle adjustment block 71. Wing nut 80 may be welded orpermanently fixed to the first angle adjustment block 71. Alternatively,bore 76 may be threaded to engage the threads of screw 78, with wing nut80 omitted altogether. The second angle adjustment block 73 defines asecond elongated, arcuate slot 88, preferably semicircular in shape andcentered about the axis of pivot joint 60, in which is received thethreaded shaft of the angle adjustment screw 78. When tightened, thegraspable head 81 frictionally engages a front surface of the secondangle adjustment block 73 to hold the lower plate 58 in one of aplurality of angular positions by frictionally securing the second angleadjustment block 73 between the first angle adjustment block 71 and thegraspable head 81.

The second angle adjustment block 73 is preferably graduated withangular markings 79 such that the lower plate 58 can be pivotallyadjusted relative to the upper plate 56 at a known angle therebetween.The angular markings preferably include graduations of 1 degree spanningfrom zero to 45 degrees. This allows the user to cut the material at aknown angle. For instance, the user can cut through wood trim pieces ata 45-degree cut angle.

Referring to FIGS. 2, 10, and 16, a vacuum housing 90 is coupled to themotor casing 38 and a blade shroud or upper blade enclosure 110, withbolts. The vacuum housing 90 forms part of saw casing 31 and includes amain housing portion 92, an impeller housing portion 94, and a impellercover 97. The main housing portion 92 defines a pressure-equalizingchamber 96 (or pressure chamber 96) and the impeller housing portion 94and impeller cover 97 together define an impeller chamber 98 (see FIG.16). The generally cylindrical impeller housing portion 94 forms asubstantially tangentially extending exhaust port 95. The impeller cover97 is mounted to the impeller housing portion 94 using fasteners Fdisposed in through bores T defined in the impeller cover 97 andthreaded into bores B in the impeller housing portion 94. Cover 97 hasgear housing 136 formed on its exterior planar surface. Housing 136 may,in some embodiments, have a separately attached outer planar cap 138 tofacilitate cover 97 being molded with the side walls of housing 136.

A plurality of through bores 101 are also defined through the mainhousing portion 92 are mated to holes 105 in impeller housing portion94, which receive fasteners (not shown) to mount the main housingportion 92 to the motor casing 38 at a first end of the motor casing 38.

An impeller 100 is rotatably supported in the impeller chamber 98 on astub shaft 135, which extends through aperture 106 of cover 97 and intogear housing 136, wherein it is rotatably supported and axially fixedrelative to central hub 103 of cover 97, by a sealed bearing 104 mountedon the outward side of hub 103, within gear housing 136. The axiallyoutward end of stub shaft 135 disposed in gear housing 136 has worm gear336 formed thereon, which is enmeshed with worm 338 provided on the endsegment 129 of flexible shaft 128, which is attached to gear housing136. The motor 32 rotatably drives the impeller 100 through flexibleshaft 128 in the direction indicated by arrow 26 to create airflow andcorresponding vacuum pressure in the pressure-equalizing chamber 96. Theimpeller 100 can be formed of metal or plastic materials such as Lexan®,nylon, or other relatively rigid plastic materials.

Referring specifically to FIG. 4B, a bore 99 is defined through end cap118 of saw casing 31, which is fixed to motor casing 38. Attached to endcap 118 is end segment 102 of flexible drive shaft 128 (see FIG. 2).Drive shaft end segment 102 is adapted for receipt into bore 99 androtatably fixed to motor drive shaft 36. Flexible drive shaft 128, whichincludes rotating, torque-carrying flexible cable disposed within aflexible surrounding, nonrotating casing or sheath, is of a typewell-known in the power transmission art that is available from a numberof sources such as, for example, S.S. White Technologies, Inc. ofPiscataway, N.J., or Suhner Manufacturing , Inc. of Rome, Ga.

Referring to FIGS. 10-12, the impeller 100 has circular plate 122 thatsuperposes the inside planar surface of cover 97, and to which aplurality of blades 124 or fins are interconnected. Circular plate 122has a central hub 130 extending normally therefrom to which blades 124are also interconnected, and from which they extend radially outwardly.Hub 130 defines a central bore into which stub shaft 135 is inserted,with impeller 100 and stub shaft 135 rotatably and axially fixedtogether. Impeller 100 and shaft 135 may be interfixed through aninterference fit, clamped engagement, or through fasteners, for example.

Planar wall 120 of housing portion 94 defines an aperture 126 thatapproximates a size of the pressure-equalizing chamber 96 such that thepressure-equalizing chamber 96 opens directly into the plurality ofblades 124. The pressure-equalizing chamber 96 opens into the impellerchamber 98 in a direction generally transverse to, and preferablyperpendicular to, plate 122 of impeller 100.

Referring specifically to FIG. 16, a plurality of vacuum conduits 406are disposed about the saw casing 31 and extend laterally therealong,between saw blade shroud or upper enclosure 110 and main housing portion92 of vacuum housing 90. In the depicted embodiment, three vacuumconduits 406 are utilized. The vacuum conduits 406 communicate with thepressure-equalizing chamber 96 through openings 109 in the main housingportion 92 (see FIG. 10). It should be appreciated that more or fewervacuum conduits 406 could be employed. The vacuum conduits 406 extendbetween upstream ends located at enclosure 110, and downstream endslocated at main housing portion 92. The pressure-equalizing chamber 96assists in equalizing the vacuum or suction pressure drawn in each ofthe vacuum conduits 406 by providing a volume of space, upstream of theimpeller 100 and downstream of the vacuum conduits 406, in which asuction pressure can be established.

In the depicted embodiment, the vacuum conduits 406 are formed inmultiple segments defined by casing components or other components thatdefine the conduits. These components may be connected together by beingsealably interfitted, or through the use of adhesive and/or couplers,and/or the like. Referring to FIG. 16, the sequentially encounteredsections of conduits 406 along the general direction of airflow aredescribed as duct heads 408, tubes 410, right-hand handle passages 412,left-hand handle passages 414, mid-body passages 415, and vacuum housingpassages 422. Mid-body passages 415 are defined by the cooperatingsemi-cylindrical surfaces 416 formed on mid-body motor casing enclosure46 and semi-cylindrical surfaces defined by mid-body window 420 attachedto enclosure 46. Passages 422 in main housing portion 92 of vacuumhousing 90 define individual outlets of vacuum conduits 406 that eachopen into pressure equalization chamber 96.

The vacuum conduits 406 preferably have a generally circularcross-section, but their cross-sections may instead be generallyrectangular in shape or other shapes, and can vary in cross-sectionalshape over their lengths. Each of the vacuum conduits 406 preferably hasa cross-sectional area at the blade shroud or upper enclosure 110 thatis larger than the cross-sectional area at the main housing portion 92.The cross-sectional area may taper gradually from the upper enclosure110 to the main housing portion 92. Three vacuum conduits 406 areillustrated and include a first or leading vacuum conduit, a second orcenter vacuum conduit, and a third or trailing vacuum conduit.

Referring to FIGS. 2 and 15, the upper enclosure 110 at least partiallyencloses an upper portion of the saw blade 34, and defines an uppersection of a debris accumulation chamber 112 (see FIG. 15). The upperenclosure 110 has a generally semi-circular shape that approximates theshape of the saw blade 34. The upper enclosure 110 is generally U-shapedin cross-section taken in planes containing the axis of rotation of sawshaft 116, except at the openings to vacuum conduits 406.

The inlets to the first and second vacuum conduits are disposed at afront section of the upper enclosure 110. The inlet to the third vacuumconduit is disposed at a rear section of the upper enclosure 110. Thefront section is defined as the front half of the upper enclosure 110,while the rear section is defined as the rear half of the upperenclosure 110. The first vacuum conduit is preferably located at thefrontmost location on the front section to collect debris at the frontof the debris accumulation chamber 112. The third vacuum conduit ispreferably located on the rear section to collect debris at the rear ofthe debris accumulation chamber 112. Together the vacuum conduits 406define separate vacuum paths for the debris.

A plurality of duct heads 408 a, 408 b, 408 c are integrally formed withthe upper enclosure 110 (or alternatively can be formed separately), anddefine inlets to their respective conduits 406. The duct heads 408 a,408 b, 408 c each have a surrounding collar adapted to receive andsealably engage the respective upstream ends of tubes 410 a, 410 b, 410c. The upstream ends of tubes 410 a, 410 b, 410 c may form aninterference fit with the collars or be adhesively bonded to thecollars.

An inner side 150 of the upper enclosure 110 is mounted to thetransmission casing 35 to close the debris accumulation chamber 112 onthe inside. More specifically, inner side 150 is integrally connected toan outer rim 145, which surrounds intermeshed gears 320, 322 oftransmission, and integral wall 146. Gear plate 51, outer rim 145, andwall 146 together define transmission casing 35. In theblade-surrounding portion of enclosure 110, the inner side 150 and anouter side 152 of upper enclosure 110 are interconnected by integral,semi-circular shoulder 155.

Outer side 152 of the upper enclosure 110 defines a semicircular opening153 in which is disposed a side window 160 that closes the opening 153and the outward side of debris accumulation chamber 112. The side window160 includes a transparent section 162 formed of transparent plastic andhas a semicircular outer periphery 164 in which is a circumferentialdistribution of holes 166 (see FIG. 18). The transparent section 162allows the user to view the saw blade 34. The outer periphery 164interfaces and abuts the inner surface of outer side 152 along theperiphery of opening 153 that is provided with holes 168 thatcorrespondingly align with holes 166. Fasteners (not shown) extendthrough aligned holes 166, 168 to secure window 160 to enclosure 110.Side window 160 includes arcuate slot 170 centered abut the axis ofrotation of blade 34. The slot 170 is adapted to receive shaft 172, theend of which is fixed to outer side 205 of manually retractable lowerblade guard 200. The outward end of shaft 172 is provided with knob 174which may be grasped by the operator to manually move shaft 172 alongslot 170 to retract lower blade guard 200 into upper blade enclosure 110to expose the edge of blade 34, which is desirable for making plungecuts into the surface of material M, rather that from an edge thereof.Lower blade guard 200 may be rotatably biased into its extended positionin which it shields the edge of blade 34, by a tension spring 175operably engaged with enclosure 110 and guard 200, in a conventionalmanner well-known in the circular saw art.

Upper blade enclosure 110 defines bottom edge 182 and side window 160defines bottom edge 176. Bottom edges 176 and 182 are substantiallyflush and lie in a plane. Referring to FIGS. 4A and 18-20, a flexiblemain bellows 180 interconnects bottom edges 176, 182 along acorresponding upper rim or edge 188. The flexible bellows 180 isflexible and expandable between compressed and extended states toaccommodate differing cutting depths, i.e., when the lower platformassembly 54 is raised and lowered relative to blade 34 to provide moreor less blade cutting depth. Flexible main bellows 180 has oppositelongitudinal ends 194, 195 that face each other, and slidably engagerespectively interfacing, parallel planar sides 196, 197 of bladeenclosure 110. Bellows 180 has lower rim or edge 186 that isinterconnected with corresponding upper rim or edge 190 of transparentblade window 192. Blade window 192 has the same general shape as mainbellows 180, and may be molded of a suitable transparent, substantiallyrigid plastic material, to allow the operator to view the cut line.Bosses 193 are formed in blade window 192 through which fasteners Fextend to secure blade window 192 to deck plate 56. Bottom edge 198 ofblade window 192 is closely received into blade opening 62, and itsoutward side has a shoulder 199 that abuts deck plate 56 along the outerlongitudinal edge of opening 62. Blade window 192 has oppositelongitudinal ends 212, 213 that face each other, and abut and sealagainst respectively interfacing, parallel planar sides 196, 197 ofblade enclosure 110.

More particularly, upper rim 188 of main bellows 180 may define aperipheral groove adapted to receive the bottom edges 176, 182 of sidewindow 160 and upper enclosure 110, and lower rim 186 of main bellows180 may similarly define a peripheral groove adapted to receive upperedge 190 of transparent blade window 192. The bottom edges 176, 182 andthe upper edge 190 may be press-fitted and adhesively sealed in therespective peripheral groove of bellows 180. In one embodiment, theflexible bellows 180 has an accordion shape. In other embodiments, theflexible bellows 180 is formed of a stretchable plastic material capableof stretching greater than 100% such as polyurethane. The flexiblebellows 180 is also preferably transparent.

Additionally, the portion of the upper surface of deck plate 56immediately below transmission casing 35 of enclosure 110 and along thelongitudinal inward edge of blade opening 62 is recessed below theadjacent portions of the deck plate upper surface. The recessed portion218 of deck plate 56 defines a planar floor 220 that is parallel withplanar bottom surface 222 of transmission casing 35, which extendsbetween its opposed sides 196, 197. Extending the entire length ofrecessed portion 218 and surface 222 is rear bellows 178. Top surface224 of rear bellows 178 is sealably attached to transmission casingbottom surface 222; bottom surface 226 of rear bellows 178 is sealablyattached to floor 220. Thus, the blade-containing space between bladeopening 62 in deck plate 56 and chamber 112 of upper blade enclosure110, is substantially sealed against air leakage through its enclosingwalls.

The inward longitudinal edge of blade opening 64 in base plate 58 islaterally distanced from blade 34 to an extent that it is positioned onthe side of recessed portion 218 that is opposite the blade 34.Extending the length of blade opening 64 is U-shaped lower bellows 181,which may be of a material similar to main bellows 180. The legs 228,229 of lower bellows 181 extend substantially perpendicularly from itselongate body 230; top and bottom surfaces 231, 232 of lower bellows 181are respectively sealably attached to the interfacing, superposedsurfaces of deck plate 56 and base plate 58. As lower platform assembly54 is adjusted about pivoting joints 60, to angle deck plate 56 and baseplate 58 between zero and 45 degrees, lower bellows body portion 230 isexpanded and contracted, while at the terminal ends of legs 228, 229bellows 181 remains compressed to a substantially consistent degreeregardless of saw blade angle. Thus, bellows 181 is arranged to enclosea portion of the space between plates 56, 58 into which blade opening 64communicates.

On the outward lateral side of blade 34, elongate, substantially planarslider plate 61 extends along the entire length of blade opening 64 inbase plate 58. The opposed ends 234, 235 of slider plate 61 arepivotally attached to deck plate 56 near the upper slider plate edge236, which slidably abuts elongate sealing flange 240 integrally formedon the deck plate and projecting upwardly and outwardly from its upperplanar surface at an angle, away from blade opening 62. The opposed ends234, 235 of slider plate 61 are closely fitted between a pair ofupstanding planar sealing flanges 242, 243 located at oppositelongitudinal ends of blade opening 64. The lower slider plate edge 237is in sliding engagement along its length with the adjacent planarsealing surface 244 of base plate 58 located between its upstandingflanges 242, 243. As slider plate 61 pivots relative to deck plate 56,with relative angular movement between deck plate 56 and base plate 58about pivot joints 60, slider plate lower edge 237 sealably slides alongbase plate sealing surface 244, and slider plate ends 234, 235 sealablyslide along the adjacent sealing surface of their respective flanges242, 243. The opposed ends 234, 235 of slider plate 61 may be slidablylinked, for example, via pin-in-slot joints, with flanges 242, 243, toensure sealing engagement between slider plate lower edge 237 and baseplate sealing surface 244. Alternatively, slider plate 61 may bepivotably biased relative to deck plate 56, for example by a torsionspring (not shown), to ensure sealing engagement between slider platelower edge 237 and base plate sealing surface 244. Alternatively, sliderplate 61 may rely on gravity and/or the air pressure differentialbetween its opposite planar sides during saw operation to ensure sealingengagement between slider plate lower edge 237 and base plate sealingsurface 244. Thus, the blade-containing space between blade opening 64in base plate 58 and chamber 112 of upper blade enclosure 110, is alsosubstantially sealed against air leakage at locations below deck plate56. The above-described sealing of the blade containing space againstthe influx of air leakage downstream of (i.e., above) blade opening 64in lower plate 58 helps to maintain general sealing of the debrisaccumulation chamber 112 when the lower plate 58 is pivoted for angledcuts. In other words, during saw operation a working vacuum pressure ismaintained in the debris accumulation chamber 112 to draw the debris outof the debris accumulation chamber 112 at all cutting angles and depths.

Referring to FIGS. 4A, 17A, and 17B, a lower blade guard 200 ispivotally mounted to the fixed collar 206 of the gear plate 51. Thelower blade guard 200 includes an inner side 203 and an outer side 205.The lower blade guard 200 includes a hub 202 on the inner side 203 forsupporting a sealed bearing 204. The sealed bearing 204 is disposed overthe fixed collar 206 and is fixed to the fixed collar 206. The saw shaft116 rotates within bearing 204 of the fixed collar 206. Thus, the fixedcollar 206 is fixed from rotation. As a result, the lower blade guard200 pivots about the fixed collar 206 via the sealed bearing 204. Thelower blade guard 200 at least partially encloses a lower portion of thesaw blade 34. The lower blade guard 200 also defines a plurality ofopenings 208 in the inner side 203 and part of the shoulder 210. Whenguard 200 is fully retracted, the openings 208, which generallycorrespond in size and location to the inlets to conduits 406 in theupper enclosure 110, become aligned with the duct heads 408 a, 408 b,408 c. A bottom shoulder 210 spaces the inner side 203 from the outerside 205.

This lower blade guard 200 rotates further into the upper enclosure 110as the saw blade 34 cuts through the material M in a conventionalmanner. Referring to FIG. 15, when the lower blade guard 200 is rotatedinto the upper enclosure 110, the openings 208 assist in providingaligned airflow paths to carry the debris to the vacuum conduits 406.This is best illustrated in FIG. 15. When the lower blade guard 200 isrotated into the upper enclosure 110, it still surrounds the saw blade34, just now at an upper portion of the saw blade 34. As a result, thereis a need for airflow from the debris accumulation chamber 112 to easilypenetrate through the lower blade guard and remain relatively unimpededas it continues to the vacuum conduits 406, and openings 208 assist inthis effort.

Referring back to FIGS. 1 and 2, a collection bag 300 is releasablymounted to the exhaust port 95 with a clamp or collet 302. In otherembodiments, the collection bag 300 can be mounted with a cinchingstring, elastic band, and the like. The collection bag 300 is preferablyflexible, collapsible, and easily disposable. In other embodiments, thecollection bag 300 is washable for coarse work such as cutting materialslike wood. The particular type of collection bag 300 utilized to catchand collect fine debris such as that produced in drywall cutting are incommon use in the industry and are well known in the art. The collectionbag 300 is generally porous to allow airflow therethrough, while stilltrapping debris deposited in the collection bag 300 during operation.

In one embodiment, shown in FIG. 3, the debris collection assemblyincludes an outer container 301 and an inner container 303, both clampedabout the exhaust port 95 and preferably being bags that are flexibleand collapsible. In this embodiment, the inner bag 303 may be formed ofdisposable filter materials such as a Style C Genuine Multi-Filter bagfor an Electrolux Tank. The inner bag 303 may be formed with a maximumpore size configured to prevent pass-through of particle diameters of100 microns or less, more preferably 10 microns or less, most preferably5 microns or less, and even some embodiments capable of preventing passthrough of particles with diameters of 1 microns or less. The outer bag301 may be fabricated from a synthetic or natural cloth material and beformed with pore sizes configured to prevent pass through of largermaterial such as wood chips, etc., preferably on the order or 0.5 inchesin diameter or less, 0.1 inches in diameter or less, and preferably fromabout 100 microns to about 0.1 inches in diameter.

During operation, the motor 32 drives the main drive shaft 36 (andflexible shaft end segment 102). Referring to FIG. 20, the first gear320 is fixed to the main drive shaft 36, while the second gear 322 isfixed to the saw shaft 116. The gears 320, 322 are preferably configuredto step down rotational speed of the saw shaft 116 compared to the maindrive shaft 36.

As the motor 32 drives the impeller 100, the impeller 100 rotates togenerate airflow. This airflow creates a vacuum or suction pressure inthe debris accumulation chamber 112 to draw debris from the debrisaccumulation chamber 112 into the vacuum conduits 406. From the vacuumconduits 406, the debris travels into the pressure-equalizing chamber 96and then through the inside plate 120 of the impeller 100. The impeller100 then directs the debris out of the exhaust port 95 and into thecollection bag 300.

The saw blade 34 preferably has a plurality of teeth arrangedcircumferentially about a perimeter of the saw blade 34. Each of theteeth includes a flat section protruding radially outwardly from themain body of the saw blade 34 that has a width that generallyapproximates the width of the main body and is usually integrally formedwith the main body out of a metallic material such as steel orcomposites thereof. In some embodiments, the saw blade 34 may be 10inches or less in diameter, preferably between 6 inches and 10 inches,and more preferably between 6 inches and 8 inches. The width of the sawblade 34 is 3 mm or less, more preferably 1.5 mm or less, and mostpreferably between about 0.2 mm and 2.0 mm. Other embodiments may havevarying sizes depending on the particular application or material to becut.

Each of the teeth has a kerf face that defines the kerf formed by thesaw blade 34 during cutting. The blade's kerf face can take on manydifferent shapes depending on the particular cutting application. Insome embodiments, the kerf is 2 mm or more, while in other embodiments,the kerf is 2 mm or less. In one particular embodiment, the kerf isabout 2 mm. In some embodiments carbide tips define the blade's kerfface, with the carbide tip fixed to the flat section in a conventionalmanner, such as by welding, adhesive, etc. A gullet is defined betweenthe teeth. The gullet for a saw blade of about 10 inches in diameter orless is preferably less than 1 inch, more preferably less than 0.75inches, and most preferably between 0.25 inches and 0.75 inches. Forlarger diameter saw blades, the gullet may be deeper.

Each of the teeth may also include an embossed portion on opposing sidesof the flat section that preferably extends from the carbide tip ontothe main body of the saw blade 34. The height of the two embossedportions and width of the flat section in total preferably equal or areless than the kerf width of the teeth, more preferably less than about95% of the kerf width of the teeth. The maximum height of each of theembossed portions in one embodiment may be 1 mm or less, more preferably0.5 mm or less, and most preferably between 0.1 mm and 0.5 mm. Indifferent applications, the height may differ.

The dimensions of the various elements can be varied according to theuses and designs of the cutting device 30. For example, the debrisaccumulation chamber 112 may be from 0.5 inches to 10 inches in width.In some embodiments, the upper enclosure 110, blade window 132, sidewindow 160, and bellows 180 may be unitary and formed in one-piece ofplastic. The motor casing 38, vacuum housing 90, and upper enclosure 110could also be formed in one-piece and could be formed of metal, plastic,or any combinations thereof. Additionally, the vacuum conduits 406 (alsoreferred to as debris carrying ducts 406) could be integrated into asingle duct (not shown) partitioned into separate paths to accomplishthe same objectives as the present invention.

As additional enhancements, lighting could be provided inside the debrisaccumulation chamber 112. Referring to FIGS. 2 and 14, one or more LEDs645 could also be positioned inside the debris accumulation chamber 112and actuated by a separate switch 650. In FIG. 14, the LEDs 645 aremounted inside the upper enclosure 110 on the front side. AdditionalLEDs 645 could be mounted on the opposite side of the upper enclosure110. The LEDs could be glued to the upper enclosure 110, snap fit intosockets integrally formed in the upper enclosure, or otherwise fastenedto the upper enclosure 110 using screws, rivets, and the like. The LEDs645 could be configured to automatically operate (light up) when themotor 32 is actuated by switch 44, or could be separately operated byswitch 650 (see FIG. 2). Further, a laser guide 700 could beincorporated in the cutting device 30. In FIG. 1, the laser guide 700 ismounted to an outside of the upper enclosure 110 along the uppershoulder 155. Like the LEDs, the laser guide 700 could be configured toautomatically operate when the motor is actuated by switch 44, or couldbe separately operated by switch 702. The laser guide 700 could also beseparately battery powered.

While the invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes can be made and equivalents can be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications can be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed herein, butthat the invention will include all embodiments falling within the scopeof the appended claims.

What is claimed is:
 1. A cutting device comprising: a motor for drivinga cutting blade to cut material; a shroud configured to at leastpartially enclose the cutting blade, said shroud defining a debrischamber into which material debris generated by the cutting blade duringcutting is received; a source of vacuum in fluid communication with saiddebris chamber; a vacuum conduit defining a vacuum path extendingbetween said debris chamber and said source of vacuum; and a blade guardrotatable relative to said shroud from an extended position outside ofsaid shroud to a retracted position inside of said shroud, said bladeguard defining an opening configured to provide communication betweensaid debris chamber and said vacuum conduit.
 2. The cutting device asset forth in claim 1 wherein said opening is configured to be alignedwith said vacuum conduit when said blade guard is in said retractedposition.
 3. The cutting device as set forth in claim 1 including aplurality of said openings to provide communication between said debrischamber and said vacuum conduit.